This invention relates to a mineral mining installation having a longwall structure, such as a conveyor, and a roof support assembly constituted by a plurality of side-by-side roof support units, at least some of which are provided with hydraulic bracing rams for bracing the longwall structure longitudinally.
In known installations of this type, each bracing ram is pivotally mounted between the longwall structure and the floor sill of one of the roof support units, the rams being inclined at small acute angles to the longitudinal axis of the longwall structure. The floor sills are provided with brackets for the connection of the bracing rams. (see U.S. Pat. No. 4,227,833).
This type of installation, which has bracing rams distributed along the entire length of the longwall structure, has proved satisfactory in practice. Unfortunately, however, the bracing rams are positioned in the access area defined between the longwall structure and the roof support assembly. The bracing rams do, therefore, greatly impede the passage of mine personnel through the access area, and this is particularly troublesome where shallow seams are being won.
The aim of the invention is to provide a mineral mining installation whose longwall structure can be reliably braced in the longitudinal direction, without leading to undesirable congestion of the access area.